Royal Purple 5W20 - 2133 miles - Mazda RX8

[unDummy]

Yep, I do agree. RP is hit or miss with certain engines. With this UOA being the 3rd(?) fill, RP is one oil to avoid in this engine.

The 4:7 oil capacity change is torturing every Rx8 out there. Thats a 57% oil change. I understand that Greddy makes an oil pan that holds an extra quart of oil. Not only will that help control temperature, reduce wear/fuel/insoluble saturation, it would turn the OCI into a 5:8 change, ~63%. If the pan fits, I'd invest there before the extra oil coolers.

 

[OMCWankel]

An update on this thread. The RX8 died last week, at 49,100 miles. The motor has lost compression, and will need a re-built rotary engine. I cut my losses, and traded it in for a new Miata, my third. I do not wish to change motors every 50,000 miles. I believe that Mazda has an engineering problem, that my not be fixable without an internal re-design. My RX-7 contacts are astonished that I use only 1/4 quart of oil every 1000 miles. They use a whole quart in the same distance. This may be the key, or it may be something else. Best of luck to all the RX-8 owners out there, and I hope you do not join the new engine club!

 

[globey]

Sorry to hear about the RX8 going down. My friend owned a late 80's RX-7 brand new. It was a beautiful car. I'm not too versed on the Rotary engines, but it's a rare event that I see older RX-7's cruising around the street.

I hope your new Miata fares better.

 

[JAG]

Sorry to hear this. My wife wanted an RX8 so badly but I told her the engine is not trustworthy.

 

[Bror Jace]

Wow, this is really surprising.

With those (decent) UOAs, I would never have guessed this motor was about ready for the boneyard. I would have thought we'd see really outrageous wear the last oil change interval or two ... maybe approaching triple digit PPM?

 

[Mokanic]

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An update on this thread. The RX8 died last week, at 49,100 miles. The motor has lost compression, and will need a re-built rotary engine. I cut my losses, and traded it in for a new Miata, my third. I do not wish to change motors every 50,000 miles. I believe that Mazda has an engineering problem, that my not be fixable without an internal re-design. My RX-7 contacts are astonished that I use only 1/4 quart of oil every 1000 miles. They use a whole quart in the same distance. This may be the key, or it may be something else. Best of luck to all the RX-8 owners out there, and I hope you do not join the new engine club!

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You answered the question I was going to ask before I could ask it. Many of these engines are/have been dropping like flies and Mazda has stepped up to deal with it. The failing engine was the reason for the poor UOA. Sorry RP haters. Maybe next time.

 

[JAG]

When machines fail, they usually produce much larger wear particles which typical UOA wear metals won't reflect. Testing that can measure the larger particles is what's needed but this engine probably would have died no matter what changes the owner could have made.

 

[Mokanic]

That may be true. I was simply commenting on how quickly some will condemn an oil from one UOA. It's not even close to being scientific or accurate by doing that. In this particular case the owner of the Mazda filled in the missing blanks by letting us know what happened to the rotory engine shortly thereafter. No good engine oil could have prevented what happened to his engine. I thought Mazda's problems with that engine was common knowledge by now. I think the rotory engine is better suited to aircraft applications. They have had problems with low compression on them for years. I remember working down the street from a Mazda dealer years ago and in the winter they would hook the manual transmission RX-7s to a truck and drag them down the road in gear to get them to start in cold weather

The "rebuilt" rotory engines were a mess. The cases did not match and they never lasted long.
Many owners or the RX-8 have paid big bucks for them only to have this happen to them. I think the owner made a good decision to get free of the thing.

 

[badtlc]

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That may be true. I was simply commenting on how quickly some will condemn an oil from one UOA. It's not even close to being scientific or accurate by doing that. In this particular case the owner of the Mazda filled in the missing blanks by letting us know what happened to the rotory engine shortly thereafter. No good engine oil could have prevented what happened to his engine. I thought Mazda's problems with that engine was common knowledge by now. I think the rotory engine is better suited to aircraft applications. They have had problems with low compression on them for years. I remember working down the street from a Mazda dealer years ago and in the winter they would hook the manual transmission RX-7s to a truck and drag them down the road in gear to get them to start in cold weather

The "rebuilt" rotory engines were a mess. The cases did not match and they never lasted long.
Many owners or the RX-8 have paid big bucks for them only to have this happen to them. I think the owner made a good decision to get free of the thing.

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I was talking to a mazda tech last week about the rotary and their problems. He said mazda feels the engines are having a lot of problems because they aren't being driven hard enough. He said they see a ton of carbon buildup from their older owners who baby the cars. You think there is any credence to that?

 

[kapps]

Hmm... a good 'ol Italian tune-up on a Mazda

 

[Loobed]

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... if it makes you feel better, RP 5W-30 has been one of the worst performers to date in the 350Z, so it's not just your engine it doesn't do so well in.
Will

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(opinion)

Royal Purple su(ks!!

it's that simple.

This is not the first bad UOA with RP

It's the "NEW" Grape Kool-Aid, have a drink

 

[buster]

I would have to agree and say RP is probably the most overrated oil I can think of.

 

[Camu Mahubah]

So sorry to hear about the loss of your Wankel.... I thought these motors were super reliable, in fact someone told me the RX-7 rotary from the 80's was the first engine to go one-million without a rebuild. I guess that was a myth. I have always wanted an RX-8. Did Mazda offer to replace or rebuild your motor? Also, I know this might get me in a bit of trouble but I think 5w20 is ridiculously too thin for any car in Florida. I think a straight 20w would be better than a 5w20 in Florida in a rotary! I could be wrong, I usually am 50% of time...

 

[ThirdeYe]

The problem with the rotaries is that they're prone to lose compression..

(edit: someone already mentioned this, sorry!)

 

[Mokanic]

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That may be true. I was simply commenting on how quickly some will condemn an oil from one UOA. It's not even close to being scientific or accurate by doing that. In this particular case the owner of the Mazda filled in the missing blanks by letting us know what happened to the rotory engine shortly thereafter. No good engine oil could have prevented what happened to his engine. I thought Mazda's problems with that engine was common knowledge by now. I think the rotory engine is better suited to aircraft applications. They have had problems with low compression on them for years. I remember working down the street from a Mazda dealer years ago and in the winter they would hook the manual transmission RX-7s to a truck and drag them down the road in gear to get them to start in cold weather

The "rebuilt" rotory engines were a mess. The cases did not match and they never lasted long.
Many owners or the RX-8 have paid big bucks for them only to have this happen to them. I think the owner made a good decision to get free of the thing.

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I was talking to a mazda tech last week about the rotary and their problems. He said mazda feels the engines are having a lot of problems because they aren't being driven hard enough. He said they see a ton of carbon buildup from their older owners who baby the cars. You think there is any credence to that?

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Personally,No. If carbon is the problem now then it's always been a problem. I do not think rotary engines handle the start and stopping and hot and cold cycles well at all. Anyone with any experience with working on them will tell you they have had low-compression problems for years.

 

[Mokanic]

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... if it makes you feel better, RP 5W-30 has been one of the worst performers to date in the 350Z, so it's not just your engine it doesn't do so well in.
Will

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(opinion)

Royal Purple su(ks!!

it's that simple.

This is not the first bad UOA with RP

It's the "NEW" Grape Kool-Aid, have a drink

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Do you have trend analysis results to back that statement? Not one or two oil changes after having the ---- run out of it at the strip. One or two oil changes is not enough to determine how well any oil is going to perform over the long run. It gives you just enough ammo to make ignorant statements which is all some want to do anyway.

 

[Bror Jace]

As long time members may know, I'm no fan of Royal Purple. I believe it to be longer on hype and bling than real performance. But, I've long run out of venom for most oils, so, no bashing was intended by any of my responses in this thread. In fact, we've some applications where RP branded products (engine oils, gear oils, etc ...) do fairly well.

The UOAs and use of the oil in this application suggest to me that the user was better off sticking to a less expensive oil that seemed to do just as good if not better.

Nor did I imply that this engine's failure had anything to do with the brand, weight or type of oil used.

I was simply amazed that we didn't see signs of really serious wear in any of the UOAs. I understand that when an engine fails catastrophically, a great deal of the wear will be in large chunks which will be left behind in the engine, oil filter, etc ... but still, I'd expect wear rates leading up to that point to be double, triple, quadruple, etc ... what would be considered 'normal.'

 

[unDummy]

There really isn't anything wrong with the rotary. I've seen several go 200k+ without issues. This is a great engine and needs little to be perfect. I also do NOT see it as prone to lose compression.

The big problem is with lubrication. Mazda decided to condemn the rotary with motor oil injection. It would've been so much better to use a separate oil injection reservoir. But, I guess marketing got that best of that. Can't expect a consumer to have the sense to top off a separate special oil sump.

The 2nd problem is emissions. How much oil can you inject and expect a passing smog test for 150k miles, or whatever big brother expects these days? Run it oil lean and expect it too last?? Rotaries tend to have hotter exhaust temps. How long do you expect that catalytic to last? So, the engine runs for optimum A/F ratios and timing for catalytic life, along with A/F ratios and oil injection for emissions. Pig rich and no oil is a recipe for disaster.

Concerning owners driving style, rotaries should be driven hard, never taken on short trips, and always allowed to fully warm up after a start. With $4 per gallon gasoline, I cant believe the number of rotary owners trying to get good MPG. Yep, the ol' Italian tuneup, DAILY, would be a dream for all those babied engines.

It also doesn't help that Mazda has a relatively long OCI for those 1/2 oil changes. And, many rotary owners don't know how to use a dipstick.

OMCWankel explains the 'REAL' reason why his engine lost compression. He was buring 8 ounces of oil every 1000-2000 miles. If you see 20mpg(optimistically), thats 50-100 gallons of gas used. Anyone think 8 ounces per 50-100 gallons is acceptable? What was Mazda thinking? Or, could the oil injectors, or its pump, have been defective?

I also have my own issues with mixing rotaries with automatics. With the current shift tuning of automatics, I just don't see it as a good match.

Rotaries engine can fail with NO UOA warning. A simple spring failure losing its tension, and poof, no compression. A seal getting stuck in the housing, or simply falling out, and poof, no compression. Too bad this engine will be replaced by dealer under warranty. We will never know what part(s) failed and what caused them to fail.

How many ecu flashes has Mazda offered for the 8? how many years did it take them to 'supposedly' admit that additional oil injection duty cycle was needed? IMO, Mazda still has a long way to go.

 

[deven]

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So sorry to hear about the loss of your Wankel....

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I started laughing out loud at 4am...

 

[badtlc]

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Personally,No. If carbon is the problem now then it's always been a problem. I do not think rotary engines handle the start and stopping and hot and cold cycles well at all. Anyone with any experience with working on them will tell you they have had low-compression problems for years.

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The tech said it has always been a problem. He cited as an example how you never see any RX-7s on the road anymore. The RX-7 had insane numbers of engine failures, too.